Measurement, modeling, and analysis of ozone and its key precursors in the southeast United States national parks

Lower tropospheric ozone (O₃) continues to be a major air pollution problem in the southeast United States due to its adverse effects on humans and the environment. This study presents measurements, modeling, and interpretation of ozone (O₃) and its key precursors in three Southeast US National Parks: Shenandoah National Park (SHEN), VA, Great Smoky Mountains National Park (GRSM), TN/NC, and Mammoth Cave National Park (MACA), KY. Firstly, O₃ and NO_y chemistry are addressed based on measurements collected from these national park sites in an attempt to assess the impact of new O₃ National Ambient Air Quality Standard (NAAQS) on regional nonattaimnent. Recognizing that nitrogen oxides are crucial to O₃ production in rural Southeast US, further investigation is conducted to identify emission source attribution, origin, and processes responsible for nitrogen oxides present in the Southeast National Parks using numerous observation-based and modeling techniques. Finally, the long-term trend, temporal distributions, influencing areas, and case studies of high ozone episodes observed at the national parks are examined. Recommendations of further data collection and modeling study for future research are given on the basis of the results from this study at the end of this dissertation.